Aseptic meningitis

Definition

Aseptic meningitis is an illness that appears similar to bacterial meningitis. However, bacteria do not grow in cultures of the fluid around the brain and spinal cord (cerebrospinal fluid). This may occur because there are no bacteria, or because the bacteria are difficult to grow.

About half of aseptic meningitis cases are caused by coxsackie virus or echovirus, two members of the enterovirus family. The rate of enteroviral infections increases in the summer and early fall. Enteroviruses are spread by hand-to-mouth contact and coughing. They also may be spread by contact with fecal matter.

Signs and tests

Physical examination may show:

Fast heart rate

Fever

Stiff neck

For any patient who is suspected of having meningitis, it is important to perform a lumbar puncture ("spinal tap"), in which spinal fluid (known as cerebrospinal fluid, or CSF) is collected for testing.

Treatment

Treatment is needed for fungal or mycobacterial causes of aseptic meningitis. Herpesvirus or varicella (chickenpox) virus may be treated with antiviral medicines. Treatment for noninfectious causes consists of pain medications and managing complications, if they occur.

No specific treatment is available for enteroviral or most other viral forms of aseptic meningitis.

Expectations (prognosis)

Unlike other forms of meningitis, aseptic meningitis caused by a virus is usually a harmless disease. Less than 1% of patients have lasting symptoms. People usually recover fully 5 - 14 days after symptoms start.

Fatigue and lightheadedness may last longer in some people.

Complications

An infection of the brain (encephalitis) may develop, though this is rare. The infection may last much longer in a person with a weakened immune system.

Calling your health care provider

Call your health care provider if you have symptoms of aseptic meningitis.

Prevention

To reduce the risk of developing an infection that can become meningitis: